UK company processes fly ash from coal plants

In addition to carbon emissions, fly ash is one of the biggest waste by-products created by coal-fired power stations, but a UK company has recently fired up an innovative reprocessing plant that will turn millions of tonnes of the ash into compounds for use in products ranging from aircraft paint to automotive components.

RockTron Limited has completed construction of an 800,000-tonne-per-year fly-ash mineral reprocessing plant at the 2,000-megawatt (MW) Fiddlers Ferry coal-fired plant near Warrington, England. The plant is designed to run 24 hours a day, seven days a week, turning new and old fly ash into manufactured minerals and materials for industries ranging from construction to aerospace.

Funded by private investors and Scottish and Southern Energy plc, the power plant's owner, the RockTron plant is capable of dealing with 200 tonnes of pulverized fuel ash (PFA) per hour, as well as millions of tonnes of ash dumped for long-term storage in four nearby manmade ponds.

The RockTron PFA Beneficiation Process extracts a wide range of products from the ash, including microscopic glass spheres, cenospheres, carbon and magnetite. The extracts are used as high-performance, low-cost fillers in cement-based products, as well as more diverse products like car components, water filters and lightweight aircraft paint. Automotive manufacturer Ford Motor Company is talking with the company about potentially creating lightweight car components.

RockTron claims that the process leaves no unusable waste and allows power companies to spend less on landfill permits and reduce their environmental footprints. Once the stockpiled fly ash has been reprocessed and reused by industry, the power station storage site and land can be remediated, enabling it to be returned to its prior state or re-designated for commercial, industrial or other use.

After 40 years of operation, more than 15 million tonnes of ash are stored in the ponds at Fiddlers Ferry, and this amount continues to grow by 500,000 tonnes each year. UK power stations create about 6 million tonnes of fly ash each year and an estimated 100 million tonnes of fly ash are stored near power plants throughout the country.

Rocktron owns a demonstration research and development plant, the Gale Common Ash Disposal Site in Knottingley, Yorkshire, which is capable of dealing with 3.2 tonnes of fly ash per hour. The site serves two power stations, Eggborough and Ferrybridge, which have combined fly-ash stockpiles of 35 million tonnes. The company is planning to build two plants at Gale Common, each processing 800,000 tonnes per year.

SSE is already in the process of spending 171 million euros to modernize the Fiddlers Ferry power plant in order to increase the facility's environmental standards.